This is where it's useful to know about Cialdini's Six Principles of Influence.

In this article, we'll examine these principles, and we'll look at how you can apply them to influence others. We'll also think about the ethics of doing this, and we'll explore how you can "see through" people who try to use these principles to manipulate you.
About the Six Principles

The Six Principles of Influence (also known as the Six Weapons of Influence) were created by Robert Cialdini, Regents' Professor Emeritus of Psychology and Marketing at Arizona State University. He published them in his respected 1984 book "Influence: The Psychology of Persuasion."

Cialdini identified the six principles through experimental studies, and by immersing himself in the world of what he called "compliance professionals" – salespeople, fund raisers, recruiters, advertisers, marketers, and so on. (These are people skilled in the art of convincing and influencing others.)